What does an 'isochar' represent in a fire investigation?

An isochar represents a line that connects points of equal char depth on materials that have been exposed to fire. This concept is critical in fire investigations as it helps to visualize how heat has affected different areas of a surface. By mapping out the isochar lines, investigators can ascertain not only the boundaries of fire influence but also the intensity of heat exposure over a particular area.

Understanding the depth of char can provide essential insights into the duration and intensity of the fire, contributing to the overall analysis of fire spread and behavior. It can help investigators establish patterns that might indicate how the fire developed and how it may have been fueled. In contrast, other options do not accurately define the specific characteristics that an isochar represents in fire investigation.